The present invention relates to a method and a device for indicating speed levels, intended more especially for motor vehicles.
Experience shows that the safety conditions governing road traffic are closely linked to a large number of parameters, some of which are listed below:
THE DIVERSITY OF TYPES OF VEHICLES ON THE MOVE AT THE SAME TIME, RANGING FROM THE LIGHT TO THE HIGH PERFORMANCE PRIVATE CAR AND FROM THE SMALL DELIVERY VAN TO SPECIAL TRANSPORT VEHICLES,
THE VERY DIFFERENT CAPABILITIES OF THE DRIVERS OF THESE VEHICLES WHOSE AGE, PHYSICAL CONDITION, GENERAL DRIVING SKILLS AND EXPERIENCE ARE EXTREMELY VARIED;
WIDELY DIVERSE ROAD NETWORKS CONSISTING OF VARYING WIDTHS, GRADIENTS AND PROTECTION;
THE DENSITY AND FLUIDITY OF TRAFFIC, WHICH DEPEND PARTLY ON THE PROXIMITY OF LARGE BUILT-UP AREAS, TIMES OF DAY, AND PARTLY ON THE TIME OF YEAR; AND
THE CONSIDERABLE INFLUENCE OF WEATHER CONDITIONS AND VISIBILITY ON TRAFFIC FLOW AND BRAKING CONDITIONS.
It would appear extremely difficult for any driver to be constantly aware of the interplay of these different parameters which affect his safety and that of all other road users, and a great many accidents arise solely from an error of judgement which causes him at a given moment to exceed a speed limit which is in line with safety target limits.
In order to try to find an answer to such accidents, authorities have found it necessary to control speed in the light of the quality of roads, and the length of time the driver has held a licence, but it would seem that these laws - applied uniformly to all vehicles and all classes of drivers - impose restrictions on experienced good drivers handling a well-kept high performance vehicle, yet at the same time encourage drivers who are inexperienced or lacking in skill to travel constantly at top speed even with light, low-powered cars, themselves often inadequately maintained and serviced.
We have recently seen the appearance on the market of speed level indicators with visual or audible alarm facilities, but the different devices of this type at present available are nothing more than extensions of already existing speedometers: the warning level is fixed arbitrarily by the driver, often depending on his mood and, if the truth were known, with the main object of avoiding prosecution and with no real concern for safety.